1. Field of the Invention
The present invention relates to an air conditioner. More particularly, the present invention relates to an air conditioner in which air is cooled once by a first step of heat exchange with a first refrigerant, and then is re-cooled by a second step of heat exchange with a second refrigerant.
2. Description of the Related Art
Generally, an air conditioner cools or heats a room, cleans air and removes moisture in the air to create more comfortable and agreeable indoor environment.
Among the above described functions of the air conditioner, air-cooling is performed by the following cooling cycle in which heat exchange is caused between indoor air and a refrigerant.
FIG. 1 illustrates a diagram of a cooling cycle of an air conditioner according to a related art.
As shown in FIG. 1, the air cooling cycling includes a compressor 2 in which a vaporized refrigerant is turned into a compressed air with high pressure, a condenser 4 in which the compressed refrigerant is condensed and its temperature becomes low as the refrigerant performs heat exchange with air, an expansion value 6 in which the condensed refrigerant is expanded and its pressure becomes low, and an evaporator 8 in which the low temperature and low pressure liquid refrigerant is vaporized by performing heat exchange with air.
The compressor 2 is classified into a single type having one compressor and a multi-type having at least two compressors. The single type compressor 2 is classified into an inverter type in which compression capacity varies according to load and a constant speed type in which compression capacity is constant. In the multi-type compressor 2, at least two compressors alternatively operate according to the load.
According to the cooling cycle of the related art air conditioner, indoor air is cooled by heat of vaporization of a refrigerant in the evaporator 8, and the refrigerant vaporized in the evaporator 8 is recovered to the low temperature and low pressure liquid refrigerant while it sequentially passes through the compressor 2, the condenser 4 and the expansion valve 6.
The air conditioner according to the related art has a problem as follows:
That is, in the case in which there is a big different between an indoor air temperature and a target temperature, such case being encountered at an initial operation stage of the air conditioner or when hot outdoor air is blown into the interior of a room, the air conditioner can not refrigerate air at once because the cooling capacity is not increased rapidly.